There are always some minor improvements here & there. Windows 8 has new settings inside the device manager (event history) for example.
With the action center, the network center and the device center, I don't see what else they can do. What do you want to see improved?
Since you bring it up here's my example. Using the network center as an example, if you open it up a number of the different settings are stored inside it's window while some other things toss up an old dialog window that's been around since Windows 98. Since they've already started to put most things into the main window why just stop and leave things out in their own dialog windows/boxes etc? Like when you click on Local Area connection in the Network Center and you get the old dialog box that's more or less the same that it's been for 10+ years? Why shouldn't that info just be put inside the main Network Center window like other things have, like for example Windows Firewall, that's been placed inside the main window and no longer brings up it's own separate dialog window.
Another example is what they're doing in office, most if not all of the different office options/settings appear inside the main office apps window, they don't bring up another window/box or w/e. In contrast we still have something like Internet Explorer that's been using the same old Internet Options dialog since IE5, if not older. I just think that the desktop CP should contain all of the different settings areas inside it's main Window, which is the same main window that Network Center and Device Center etc show up in, look at the address bar and you can see the path listed. I believe it's time to ditch the old dialog boxes that have been around since the 90s.